Field of the Invention
The invention relates to a device for applying a hardenable plastics coating to an inner side of a wall of a tubular construction, for example a sewage pipe, wherein the inner side of the wall of the tubular construction, after hardening of the plastics coating, is fluid-tight.
The invention also relates to a supply chamber for containing a hardenable plastic, for use in the device according to the present invention.
The invention also relates to a method for applying the coating of hardenable plastic by means of the device according to the present invention.
The invention furthermore relates to a set of a device for applying a hardenable plastics coating to an inner side of a wall of a tubular construction, for example a sewage pipe, and a device for cleaning elements of the coating applying device, particularly elements which are exposed to hardenable plastic during operation of the coating applying device.
Description of the Related Art
The fluid-tight sealing of tubular constructions generally takes place within the framework of renovation of existing pipes which are no longer fluid-tight, for example as a result of corrosion, the penetration of tree roots, calcification of the pipe, subsidence of the ground and/or fractures resulting from the movement of the construction in which they are housed. Although the present invention is particularly described for pipe parts of circular cross-section, such as sewage pipes, it will be clear to the person skilled in the art that this is purely illustrative and that the shape of the cross-section of the tubular construction to be renovated is not limiting for the device and the method according to the present invention.
A first known technique for the renovation of sewage pipes which is used is the complete replacement of a bad section of a pipe. This technique is quite drastic, since that section of the pipe which is to be replaced must be made accessible by the exposure thereof before it can be replaced. Should that section of the pipe which is to be replaced be situated outdoors under the ground, then the exposure of this section according to the above technique usually involves the necessary earthwork. Should that section of the pipe which is to be replaced be situated indoors, then it is often necessary to at least partially remove floor tiles or wall tiles before the piece of pipe to be renovated can be replaced. In both above-mentioned situations, the renovation takes a relatively long time and involves, in addition to the nuisance that goes with it, fairly high costs.
A second known technique is aimed at not physically replacing that section of a pipe which is to be renovated. This technique, which is known as “relining” or “sleeve renovation”, makes use of a so-called “liner” or inner tube, which is fitted into the pipe to be renovated and is connected to an inner wall of the pipe, for example by gluing. The “liner” or inner tube usually comprises a needle felt sleeve, possibly reinforced with glass fibre, which is impregnated with a hardenable plastic, for example epoxy resin. In the case of a needle felt sleeve, this is unrolled, by the use of air pressure, inside out into the pipe to be renovated. After this, the hardenable plastic is hardened, for example by passing UV light, warm water or steam through the “liner”. As a result, the “liner” is connected to the inner wall of that section of the pipe which is to be renovated and a seamless and self-supporting pipe is obtained in the old pipe. A drawback of this way of doing is that the diameter of the renovated pipe is smaller than the diameter of the original pipe. This need not present a problem in practice, however, since the original pipes are usually over-dimensioned, whereby a reduction in diameter as a result of “relining” need not be problematical.
Since, if the second known technique is used, the piece of pipe to be replaced does not need to be exposed, nuisance both outdoors and indoors can be significantly reduced. Because earthwork and/or cutting work can be avoided or can at least be confined to a minimum, the fitting of the “liner” or inner tube can be done relatively quickly and the costs of the renovation can remain relatively limited.
A drawback of the second known technique, especially if used indoors, is that side connections, that is to say pipes which extend between sanitary fittings, such as taps, wash basins, wall-mounted toilets, bath tubs, shower trays, etc., and sewage pipes having an internal diameter within the range of 50-100 mm, following renovation of the latter, so-called “main pipes”, cannot be tapped or jointly renovated. At present, it is therefore not possible to cost-effectively provide the above-described side connections with a “liner” according to the second known technique. Hence, it is currently necessary to replace side connections which must at least partially be renovated according to the above-described first known technique. This causes nuisance and contributes to higher costs. It is especially disadvantageous if there is a need to resort to cutting work to expose the pipe part to be renovated where luxury finishing of, for example, walls and/or floors is concerned, and/or should a certain type of finishing no longer be obtainable.
WO 2003/014613 discloses a polyurethane applicator for spraying at high-pressures a liner on the inner circumferential wall of an existing conduit to be rehabilitated. The applicator includes a carriage coaxially guided in the conduit and an atomizer rotatably mounted to the carriage for rotation about the central axis thereof. The atomizer is provided with a nozzle through which the lining mixture is forced out while the atomizer rotates and travels in conduit with the carriage.
EP 2 230 021 discloses a device for applying an internal coating in tubes which comprises a nozzle and a mixing casing arranged in connection with the nozzle and configured to receive at least two coating material components. Driving means intended to be located outside the tube to be coated and configured to drive an elongated flexible element to rotate also causes said nozzle to rotate by being connected to said flexible element while throwing said coating material substantially radially outwards towards inner walls of the tube. Mixing members inside a mixing compartment of the mixing casing are brought to carry out a stirring movement inside said compartment for mixing the coating material components arriving thereto to a substantially homogenous mixture, which is drained to said nozzle.